CentoS 7 系统 扩容根分区

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需求场景：

需要将客户物理机磁盘剩余的空闲空间分区，合并到逻辑卷，扩展根分区

当前环境：

[root@master ~]# df -h
文件系统                 容量  已用  可用 已用% 挂载点
/dev/mapper/centos-root   10T  9.5T  549G   95% /
devtmpfs                  16G     0   16G    0% /dev
tmpfs                     16G     0   16G    0% /dev/shm
tmpfs                     16G  9.7M   16G    1% /run
tmpfs                     16G     0   16G    0% /sys/fs/cgroup
/dev/vda2                2.0G  166M  1.9G    9% /boot
tmpfs                    3.2G     0  3.2G    0% /run/user/0

可以看到vda 磁盘有20T 还有10T空闲空间没有分配

[root@master ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0              11:0    1 1024M  0 rom  
vda             252:0    0 19.8T  0 disk 
├─vda1          252:1    0    1M  0 part 
├─vda2          252:2    0    2G  0 part /boot
└─vda3          252:3    0   10T  0 part 
   └─centos-root 253:0   0   10T  0 lvm  /

操作步骤：

第一步：将剩余空间分区

[root@master ~]# parted /dev/vda

(parted) print                                                            
错误: 备份 GPT 表不像应该的那样出现在磁盘的末尾。这可能意味这其它操作系统相信磁盘小一些。通过将备份移动到末尾 (并删除旧备份) 来修正？

修正/Fix/忽略/Ignore/放弃/Cancel? Fix                                     
警告: Not all of the space available to /dev/vda appears to be used, you can fix the GPT to use all of the
space (an extra 1468006400 blocks) or continue with the current setting? 

修正/Fix/忽略/Ignore? Fix                                                 
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 21.7TB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 
Number  Start   End     Size    File system  Name                  标志
 1      1049kB  211MB   210MB   fat16        EFI System Partition  启动
 2      211MB   1285MB  1074MB  xfs
 3      1285MB  537GB   536GB                                      lvm

(parted) mkpart                                                           
分区名称？  []? 4                                                         
文件系统类型？  [ext2]? xfs                                               
起始点？ 11.0TB                                                            
结束点？ 21.7TB
                                                           
(parted) print                                                            
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 21.7TB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 
Number  Start   End     Size    File system  Name  标志
 1      1049kB  2097kB  1049kB                     bios_grub
 2      2097kB  2150MB  2147MB  xfs
 3      2150MB  11.0TB  11.0TB                     lvm
 4      11.0TB  21.7TB  10.7TB               4
(parted) quit                                                             
信息: You may need to update /etc/fstab.

说明：parted 分区退出自动保存，不像fdisk需要保存

第二步：格式化分区

[root@master ~]# mkfs.xfs /dev/vda4

查看当前逻辑卷

[root@master ~]# vgdisplay 
  --- Volume group ---
  VG Name               centos
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               10 TiB
  PE Size               4.00 MiB
  Total PE              5180926
  Alloc PE / Size       5180926 / 10 TiB
  Free  PE / Size       0 / 0   
  VG UUID               jw3yqY-Ssfb-NNu3-iwDN-4CV2-d4Nq-uFL0So

第三步：逻辑化分区/dev/vda4，准备给centos逻辑卷扩容

[root@master ~]# pvcreate /dev/vda4
WARNING: xfs signature detected on /dev/vda4 at offset 0. Wipe it? [y/n]: y
  Wiping xfs signature on /dev/vda4.
  Physical volume "/dev/vda4" successfully created.

第四步：开始扩容

[root@master ~]# vgextend centos /dev/vda4
  Volume group "centos" successfully extended
[root@master ~]# vgdisplay
  --- Volume group ---
  VG Name               centos
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               19.76 TiB
  PE Size               4.00 MiB
  Total PE              5180926
  Alloc PE / Size       5180926 / 19.76 TiB
  Free  PE / Size       0 / 0   
  VG UUID               jw3yqY-Ssfb-NNu3-iwDN-4CV2-d4Nq-uFL0So

说明：磁盘空闲空间增长到19.76T,说明扩容成功

第五步：扩容/dev/mapper/centos-root逻辑卷分区

[root@master ~]# lvextend -l +100%FREE  /dev/mapper/centos-root 
  Size of logical volume centos/root changed from <10.00 TiB (2620927 extents) to 19.76 TiB (5180926 extents).
  Logical volume centos/root successfully resized.

第六步：更新逻辑卷分区的大小

[root@master ~]# xfs_growfs /dev/mapper/centos-root
meta-data=/dev/mapper/centos-root isize=512    agcount=10, agsize=268435455 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=2683829248, imaxpct=5
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=521728, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 2683829248 to 5305268224

第七步：检查是否扩容更新成功

[root@master ~]# df -h
文件系统                 容量  已用  可用 已用% 挂载点
/dev/mapper/centos-root   20T  9.5T   11T   48% /
devtmpfs                  16G     0   16G    0% /dev
tmpfs                     16G     0   16G    0% /dev/shm
tmpfs                     16G  9.7M   16G    1% /run
tmpfs                     16G     0   16G    0% /sys/fs/cgroup
/dev/vda2                2.0G  166M  1.9G    9% /boot
tmpfs                    3.2G     0  3.2G    0% /run/user/0